List all WMI extrinsic event classes recursively

Get-ExtrinsicEventClasses.ps1

function Get-Derived {
    Param(
        [String]$Class,
        [String]$Namespace
    ) 
    if (-not [string]::IsNullOrEmpty($Class))
    {
        Get-WmiObject -List -Namespace $Namespace | Where-Object { $_.__SUPERCLASS -eq $Class -and (-not ($_.Name.StartsWith('__')) ) } | foreach {
            Get-Derived -Class $_.__CLASS -Namespace $_.__NAMESPACE
            $_
        }
    }
}


function Get-ExtrinsicEvents
{
    $namespaces = Get-WmiObject -Namespace 'root' -Class '__Namespace' -Recurse | Select-Object @{N='Name';E={"root/$($_.Name)"}}
    $extrinsic = $namespaces.Name | foreach { $ns = $_; Get-WmiObject -List -namespace $_ | Where-Object { ($_.__SUPERCLASS -eq '__ExtrinsicEvent') -and -not ( ($_.Name).StartsWith('__')) } }

    $extrinsic | foreach {
        $_
        Get-Derived -Class ($_.Name) -Namespace ($_.__NAMESPACE)
    }
}